Stone-dressing tool and the like.



F. W. ROBERTS.

STONE DRESSING TOOL AND THE LIKE.

APPLICATION F1LED1UNE 30.1913.

l,l48,053 111111111011 1'111y 27, 1915.

(A 1 e f Nascita.

FREDRrcK W. Renners, oF Locxrom, NEW Yom;

v STONE-DRESSING TOOL AND THE LIKE.

Be it known that L'FREDRICK W. ROBERTS, a citizen ot the United States, residing at Lockport, in the county of Niagaral and State of New York, have invented a ynew and useful Improvement in Stone-Dressing Tools and the like, of which the 'following is a specification.

This invention relates to improvements in tools or burs of the kind used for dressing `the surfaces of pulp grinding stones.

The burs or tools commonly used for dressing pulp grindingstones consist of a single piece solid steel cylinder or -roll having a luted or toothed surface. It is the usual practice in pulp mills to recut the burs from time to time when the teeth or flutes become worn from use, asthe cost of the burs precludes the substitution of a new bur every time the teeth are worn down. The reeutting is a comparatively expensive procedure and is objectionable, because the diameter of the bur and the spacing of the teeth is changed with each recutting. lVhen a bur is put into use. unless the spacing of the teeth is exactly the same as on the bur previously used on the same stone, the teeth of the bur do not mesh properly, with the ridges on the surface ot' the stone, and the,

result is that the old surface of the stone is torn off and broken up until a new surface is formed corresponding tor the tluting on the new bur. 'lhis entails an entirely unnecessary wear on the stone. together with a complete change in the quality and quantity ofthe pulp produced.

'The object of this invention is to produce a stone dressing'bur or tool having a separate piece outer shell or portion provided with the' stone dressing surface which can be removed when the dressing surface is worn and replaced by a new shell: and also to construct the bur so as to permit of the shells being quickly and easily changed, and to insure a secure and rigid attachment of the shell to the core or body of the bur. The interchangeable shells can beA manufactured at such a small cost that an old shell can be replaced by a new one at little, if any, greater expense than recutting an old bur, and the interchangeable shells have the advantage that they are always the same as to diameter and the spacing of the teeth, so that the changing of the shell is not open to-the above noted objection of recutting the `lid burs. The interchangeable shells also Specification of Letters Patent.

Patented July 27, Jtoits.

Application led June 30, 1913. Serial N o. 776,490.

make it possible to replace a shell having one kind of teethor flutes by another having teeth or flutes of a different character.

y In the accompanying drawings: Figure 1 is a plan view of a stone dressing tool embodying the invention. Fig. 2 is a sectional elevation of the bur removed from the holder. Fig. 3 isa. perspective view of the several parts of the bur separated. Fig. 4 is an elevation ot a toothed shell with different kind of teeth. Fig. 5 is a sectional elevation of a dressing tool of modified construction.

Like vreference characters refer to like parts i' the several figures.

A represents the bur or dressing roll the surface of the grinding stone in a suitable holder orbearing member B adapted to be secured in the stone dressing machine or device. The bur comprises a cylindrical body or core C which is suitably 'ournaled in the holder or bearing member and an outer shell D which surrounds and is remov# ably secured on said core and is provided with a surface of luted, toothed or other formation suitable for dressing stone. The shell is properly tempered, but the core or body C does not have to be tempered and can be made of a cheaper grade of metal of any suitable kind. The shell shown in Figs. l to 3 is provided with continuous longitudinal surface flutes or teeth, but the shells can be made with surfaces of any other formation suitable for dressing thegrinding stones, for instance, as shown in Fig. 4, the shell D is provided with interrupted teeth or flutes. lVhen desired one shell can be replaced by another of dili'erent type, the same core or body bein adapted for use with various diferent Shel s.

For the purpose of removablysecuring the shell D on the core or body, the latter is preferably provided with a removable spindle or bearing E fitting loosely in an axial hole e in the core, and a pin F which extends through a radial hole f in--the core and has a reduced outer end entering a hole f of corresponding size in the shell D. To secure the shell in place on the core, the pin F is placed in the pin hole f in the core loefore the spindle or bearing is putin place, and the shell is then slipped onto the core and the reduced end of the pin F dropped into the hole in the shell, after which the spindle or bearing is shoved into the core.

which is journaled to rotate in contact with .\s the hole in the shell is smaller than the large inner end of the pin, the pin cannot work'outwardly through the hole in the shell. and the spindle or bearing prevents the pin trom moving inwardly out of the pin hole in the core. rI`he shell, therefore, cannot be removed from the core without lirst removing the spindle or bearing and the spindle or bearing can ,only be removed l`rom the core by taking the bur out of the holder 1, so that the shell is very rigidly and securely held in place on the core. l\\vertheless` the shells can be very quickly and easily removed and changed by taking the bur out of the holder or bearing member B.

In the construction shown in Figs. 1-5 the bur is arranged to rotate on a simple spindle C, while Fig. shows a roller bearing t'or the bur comprising a spindle II and antit'rictionrollers /t confined in a cage /i between the spindle and the core ,/2 represents dust'caps surrounding the spindle Il at the ends of the roller bearing. rI`he spindle li or the rollers i, in the Fig. 5 construction, prevent the pin I" from falling inwardly out o'll its hole in the core. In the use ol' the device the bur revolves rapidly and the pin I" is held outwardly in its hole b v centrifugal i'orce, so that there is little or no tendency for the pin to engage and wear the spindle or rollers.

l1`he holder can be made ot the ordinary forked construction shown, consistingr ot' separable halves bolted together, or of any other suitable construction which will permit the ready removal of the bur.

'hile the invention is primarily intended as an improvement in burs for dressing pulp grinding stones, the described means for securing the removable shell on the tool core or body is also applicable to other rotary tools or devices having a removable shell or outer portion.

I claim as my invention:

l. tool oi" the character described comprising a 'core, a holder in which said core is rotatably mounted, a hollow shell which surrounds and is removably fitted on said core and is provided with a stone dressingr surl'aee, and means 'lor removably securing said shell on said core comprising a member which is movable inwardly with reference to the core to release said shell, and means i'or preventing the releasing movement of said member except when said core is disconnected from said holder.

i2. A tool of the characterdescribed coinprising a core, a holder in which said core is rotatably mounted, a hollow shell which surrounds and is removably fitted on said core, a spindle for said core which is movable therein. and means for vsecuring said shell on said core. said securing means being movable to release said shell only when said spindle has been moved from its normal position in the core.

2S. Atool ot' the character described comprising a core, a holder in which' said core is rotatably mounted, a hollow shell which surrounds and is removably titted on said core, an internal securing device connecting said shell" and said core, and a removable bearing for said core which retains said securing device in holding engagement with said shell, substantially as set forth.

l. A tool. of the character described, comprising a core, a holder in which said core is rotatably mounted, a hollow' shell which surrounds and is removably fitted on said core, a pin located in a radial hole in said core and having a reduced end fitting in a hole in said shell, and a bearing for said core which retains said pin in holding engagement with said shell, and is movable to allow said pin to be moved inwardly out of holding engagement with said shell, substantially as set lforth.

A tool of the character described comprising a core, a roller bearing within said core, a hollow shell which surrounds and is removably fitted on said core, and a securing device connecting said shell and said core, said securing device being located in said core between said shell and said roller bearing, substantially as set forth.

(5. In a tool tor dressing grinding stones, a hollow cylindrical shell provided with an external toothed or roughened stone dressing surface, said shell consisting of a singlepiece tube ot tempered metal and having a hole in its cylindrical wall ior the engagelnent of a device for securing the shell on a rotary holder.

Witness my hand, this 26th day of June,

FREDRICK lV. ROBERTS. lVitnesses:

H. I". CUSHMAN, C. G. SNYDER. 

